Method of and an apparatus for measuring a person's ability to perform a motor control task

• US 6,974,326 B2
• Filed: 04/19/2002
• Issued: 12/13/2005
• Est. Priority Date: 02/08/2002
• Status: Expired due to Fees

• Current Assignee: The University of Bristol
• Original Assignee: University of Bristol
• Inventors: Marple-Horvat, Dilwyn Edwin
• Primary Examiner(s): Cheng, Joe H.
• Application Number:
  US10/125,993
• Publication Number:
  US 20030153846A1
• Time in Patent Office: 1,334 Days
• Field of Search: 434/29, 434/62, 434/64, 434/66, 434/69, 434/236, 434/238, 434/247, 434/258, 434/307.R, 434/308, 434/362, 434/365, 600/300, 600/558, 348/77, 348/114, 348/118, 180/272, 701/1, 382/118, 382/190, 382/209, 340/575, 340/576
• US Class Current: 434/236
• CPC Class Codes: A61B 5/163 by tracking eye movement, gaze, or pupil change
• CPC Class Codes: A61B 5/18 for vehicle drivers or machine operators

Abstract

An apparatus is provided for assessing a persons ability to perform tasks requiring hand and eye co-ordination. A gaze tracker 6 images a person'"'"'s eye in order to determine their direction of look. In the context of a vehicle system, a steering wheel direction sensor 12 is provided to determine the direction of the steering wheel. Data from the steering wheel sensor and the gaze tracker is compared by a data processor 14 which looks for correlations between the data sets and uses this correlation to determine whether the person 2 is fit to drive or not.

Claims

1. A method of determining whether a person'"'"'s ability to drive a motor vehicle has become impaired, the method comprising the steps of:

a) measuring eye movement made by a person in order to acquire visual data for driving a vehicle;

b) measuring a control motion made by the person in order to control the direction of the vehicle;

c) comparing the person'"'"'s eye movement with the control motion made by the person in order to obtain a measure of the person'"'"'s performance; and

d) comparing the measurement of performance with a threshold and to output the result of the comparison.

2. A method as claimed in claim 1, wherein the measure of performance is compared with a historical measure of performance and one item selected from the group consisting of issuing a warning and taking an action, is performed if the difference exceeds a predetermined threshold.

3. A method as claimed in claim 1, wherein the eye motion as a function of time and the control motion as a function of time are cross-correlated.

4. A method as claimed in claim 3, wherein the cross-correlation is analysed to determine at least one of a correlation peak value and a time displacement.

5. A method as claimed in claim 4, wherein the results from a recent cross-correlation are compared with a historical measure, and one item selected from the group consisting of issuing a warning and taking an action, is performed if the correlation peak value is less than the historical measure by a threshold amount.

6. A method as claimed in claim 5, wherein the warning is issued when a value of the recent cross-correlation peak is less than the product of an acceptance coefficient and the historical value of the cross-correlation peak.

7. A method as claimed in claim 5, wherein the results of a recent cross-correlation are compared with a historical measure by forming a non-overlapping integral and a warning is issued depending upon the size of the integral.

8. A method as claimed in claim 1, wherein the control motion is determined by measuring motion of a steering wheel.

9. An apparatus for determining whether a person'"'"'s ability to drive a motor vehicle has become impaired, the apparatus comprising:

a) an eye tracker for measuring the person'"'"'s eye movements to acquire visual data for driving the vehicle;

b) a motion sensing device for measuring a control motion made by the person in order to control the direction of the vehicle; and

c) a data processor for comparing an output of the eye tracker with an output of the motion sensing device to derive a measure of the person'"'"'s performance and to compare the measure of performance with a threshold and to output the result of the comparison.

10. An apparatus as claimed in claim 9, wherein the data processor is arranged to cross-correlate the output of the motion sensing device with an output of the eye-tracker.

11. An apparatus as claimed in claim 9, wherein the result of the comparison is compared with historical data, and one of a warning issued and a predetermined action taken if the difference exceeds a predetermined threshold.

12. An apparatus as claimed in claim 9, wherein the motion sensing device is responsive to motion of a steering wheel.

13. A motor vehicle, including an apparatus for determining whether a person'"'"'s ability to drive the motor vehicle has become impaired, the apparatus comprising:

a) an eye tracker configured to measure eye movements made by a driver to acquire visual data for driving the motor vehicle;

b) a motion sensing device configured to measure a control motion made by the driver to control the direction of the motor vehicle; and

c) a data processor programmed to compare an output of the eye tracker with an output of the motion sensing device to derive a measure of the driver'"'"'s performance and to compare the measure of performance with a threshold and to output the result of the comparison.

14. A computer program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform method steps for determining whether a person'"'"'s ability to drive a motor vehicle has become impaired, the method comprising the steps of:

a) measuring eye movement made by a driver to acquire visual data for driving a vehicle;

b) measuring a control motion made by the driver to control the direction of the vehicle;

c) obtaining a measure of the driver'"'"'s performance by comparing the eye movement made by the driver with the control motion made by the driver; and

d) comparing the measurement of the driver'"'"'s performance with a threshold and outputting a result of the comparison.